Grit removal early in the process serves primarily to prevent damage to equipment and to

• A. free up space for treating organic matter
• B. increase odor control
• C. reduce energy use
• D. prevent equipment damage and free up space for organic matter treatment

Answer: (D)

Grit removal early in the flow protects the equipment and preserves capacity for the biological treatment that follows. Grit—sand, gravel, and other heavy inorganic solids—is abrasive, so letting it travel through pumps, valves, and piping causes wear, increases maintenance, and can shorten equipment life. Removing it up front minimizes that damage. At the same time, grit takes up space that would otherwise be available for treating organic matter, so taking it out early keeps downstream treatment units free to process the organic load effectively. That combination—preventing equipment damage and freeing space for organic matter treatment—best captures the primary purpose.